Australia seems on a steep decline and a testing ground for western authoritarianism. Look at the requirements to leave the country, you need to jump through hoops and prove that your presence is required outside to be granted permission to leave. This should be unacceptable for anyone, whether you are Australian or not.
I just did a quick look, searching (without quotes) "Australia permission to leave" on DDG. It looks to me like you're conflating emergency restrictions for COVID [0] with something like the exit visas that the former USSR used and Russia still uses. There are a great many people dying in the US at this very moment who were making this same sort of argument, right up until they caught COVID and ended up on ventilator…
I seriously do not understand where the logic is here. I can understand restricting travel in, but why restrict travel out? In my mind there is no reason why someone LEAVING your country might be a health concern.
But hey we're talking about the folks that thought the logical solution to prevent people from spreading COVID at dog shelters would be to just shoot all the dogs.